2. Field of the Invention
The present invention relates generally to air bag systems and more particularly to a break-away fastening system for deployment doors which are forced away from a panel opening upon air bag deployment. The panel opening for a concealed air bag system of a vehicle is normally closed by a cover or door(s) held in place by a fastening system which is designed to fracture in a controlled manner during air bag deployment so that uncontrolled fragments of the doors, fasteners or other system components are not generated and dispersed around the area. Also, when fracture occurs, only a smooth face is presented to the expanding air bag so that damage to the air bag does not occur during rapid deployment thereof.
2. Background of the Prior Art
U.S. Pat. No. 3,822,894 to Muller et al. discloses a steering wheel having a built-in air cushion employing a strong hinge between a cover and a dish containing the air bag so that on inflation, the cover is pushed away but not completely liberated from attachment to the steering wheel.
The Wulf et al., U.S. Pat. No. 3,944,250, discloses an automatically inflatable gas cushion for the protection of passengers in vehicles employing a cover which is opened upon inflation of the air bag or gas cushion and which is retained by a flexible band so that the cover is restrained after opening.
The DiSalvo et al., U.S. Pat. No. 4,893,833, discloses a closure for an air bag deployment opening wherein an integral aluminum hinge flange on the closure is bolted to the frame of the vehicle permitting pivotal opening movement of the closure.
The Hirabayashi, U.S. Pat. No. 4,911,471, discloses an arrangement of an air bag device in a motor vehicle wherein angular pivotal movement of a door over the air bag is restricted by a strap to limit the angular degree of opening when the air bag is inflated.
U.S. Pat. No. 4,964,653 to Parker discloses a self-skinned foam closure element for an inflatable restraint door assembly having a combination hinge and tether for restraining travel of the closure element during air bag deployment.
U.S. Pat. No. 5,031,930 to Sato discloses an air bag system having deployment doors connected to air bag module side plates by small pins which are fractured upon air bag deployment to release the doors.
U.S. Pat. No. 5,064,217 to Shiracki discloses a cover for an air bag unit having "Nylon" yarn bands molded in place and wrapped around a retaining band of resin provided on the air bag enclosure or housing.
U.S. Pat. No. 5,082,310 to Bauer discloses an arrangement for providing an air bag deployment opening including a door having a weakened section which fractures to allow separate door portions to open upon air bag deployment.
U.S. Pat. No. 5,150,919 to Sakakida et al. discloses an air bag system for a vehicle having a pair of doors or lids which pivotally open in opposite direction and which are restrained by belt members so that the lids pivot about transverse axes and open smoothly upon air bag deployment.
U.S. Pat. No. 5,195,776 to Sakakida et al. discloses an air bag installation having curved air bag cover lids which are reliably opened by rotation about a center point so as not to restrict the inflation of the air bag.
U.S. Pat. No. 5,072,967 to Batchelder et al. discloses an instrument panel having an invisible air bag deployment door with weakened sections formed therein but hidden from view for facilitating fracture of the door along predetermined lines for opening movement during air bag deployment.
The Combs et al., U.S. Pat. No. 5,096,221, discloses an air bag door having plural substrates on the inside which normally retain the door in a closed position and at least one of which is notched or provided with a hidden tear seam to facilitate fracture for opening of the door.
The Catron et al., U.S. Pat. No. 5,211,421, discloses an air bag cover door retainer having bifurcated engagement flanges on the door normally retaining the door in a closed position and releasable to permit door opening during air bag deployment.
U.S. Pat. No. 5,211,422 to Frantz et al. discloses an occupant restraint system including an air bag having an upper reaction member that is initially restrained upon air bag deployment until side portions unfold and release restraints on the reaction member.
The Fujiwara et al., U.S. Pat. No. 5,199,739, discloses an air bag cover opening mechanism for a motor vehicle including a sheer pin which is severed upon opening pressure exerted on the inside of the door by the deploying air bag.
The Wang, U.S. Pat. No. 5,219,177, discloses a releasable latch for an air bag deployment door which is activated by air bag deployment to permit the door to open.
U.S. Patent to Faigle et al. U.S. Pat. No. 5,242,191, discloses a tethered air bag cover system wherein the cover is retained after opening attached to the air bag itself.
European Patent Application No. EPO 0415 362 A2 discloses an air bag supporting system having two fly-away covers restrained by loose flexible straps.
German Patent No. DE 38 43 686 A1 discloses an air bag cover for a car which is retained in one piece in relation to the dashboard of the automobile by a retaining hinge element.